The Azaranian senate is the highest body of the Azaranian Imperial Hierarchy that is elected directly by the populace. The Senate is composed, currently, of 174,536 members, from 523 colonial presidents. The amount of seats is always in flux, as one member is set as the population of the least populous colony. The number of Representatives a specific world sends is based on the population of the colonial president it is part of. A general electoral census is conducted every 20 election cycles, and, if any adjustments are to be made, the lowest population world is calculated, and then the populations of colonial presidents are tallied, and seats in the senate are given to the colonial presidents, based on that ratio, who then distribute the seats to the colonies it is responsible for. The general system most presidents use is rounding down the colony's population to the lowest number of the population ratio, distribute the correct number of representatives to the planet, and then, with the remaining representatives, they pool certain colonies together, to get the desired number of senators per population. In others, the extra senate Seats are given to the heads of colonial assemblies as a default. Other colonial presidents may do what they want with the extra seats, so long as they are elected by the people.
After an election, the Emperor of the Azarath appoints the First Senator as the most likely person to maintain the confidence of the senate until the end of their mandate (next election). Most often, it is the leader of the majority or plurality faction in the senate. The First Senator then "recommends" (and by that I mean the recommendation is accepted 99% of the time) the persons (s)he believes would best fill the now vacant positions in the high senate. A high senator's tenure terminates as soon as the new session of the senate resumes after the election.